Ocean ‘Dead Zones’ Coming, Study Finds

(CN) – Increasing acidity and low oxygen levels in the Pacific Ocean off the West Coast mirror conditions the earth will face if global warming continues to intensify, according to scientists. Significant disruptions to ecosystems and the potential extinction of various marine species are already occurring within the eastern Pacific Ocean And a panel of scientists from California, Oregon and Washington state say the problems will likely become more severe over time. “Global change is already upon us,” study co-author Dr. George Somero told Courthouse News. “We’re already seeing effects of acidification and hypoxia [low oxygen levels in the ocean] in a number of biological systems and processes.” Somero, the associate director of Stanford’s Hopkins Marine Station, explained that further exposure to carbon dioxide and other greenhouse gases will continue to disrupt bio systems, adjust the behavior of various species of marine life, and lead to the death and potential extinction for countless fish, squid and other organisms. “The dissolution of pteropod shells is particularly striking. As acidification literally dissolves their shells and causes their demise, serious consequences for food webs and fisheries seem to be in store,” Somero said. Somero and his co-authors reviewed existing research in order to determine how current variables impact the negative issues in the eastern Pacific Ocean. “The changes really stem from the basic impact to physiology, no voodoo involved,” Dr. Francis Chan, an associate professor at Oregon State University and study co-author, said. “We need to look at ocean acidification not just as one stressor, but that it’s going to be affecting organisms in the context of other things.” These effects are heightened due to the natural upwelling that occurs along the West Coast. Upwelling is when cooler, nutrient-rich water is pushed to the surface and replaces warmer water, and can lead to marine life expansion that enables significant commercial fishing opportunities. However, upwelling exposes oxygen-deprived water to the ocean surface, which then combines with carbon dioxide from the atmosphere to make a bad situation even worse. “Bacteria and lice are consuming the oxygen and releasing the carbon dioxide,” Dr. George Waldbusser, a marine ecologist and biochemist at Oregon State University, said. “The challenge is that multiple things are changing.” Waldbusser explained how hypoxia and elevated carbon dioxide levels compound existing stressors in the eastern Pacific Ocean. You essentially have a one-two punch,” Waldbusser said. “If you have warming, acidification and hypoxia all happening at the same time, it reduces the resistance of organisms to stressors. It’s synergistic in a sense.” The ocean absorbs about 25 percent of carbon dioxide released into the atmosphere annually. And even if nations around the world were able to drastically reduce their greenhouse gas emissions, it would take several decades to be fully reflected along the West Coast. “The water is four to five decades old. Even if we were to emit no carbon dioxide right now, go cold turkey, every year that the water that comes at us will still have more carbon dioxide because of the lag,” Chan said. Another study co-author, Terrie Klinger of the University of Washington’s Ocean Acidification Center, underscored the frightening reality for the rest of the planet’s oceans. “Conditions observed along our coast now are forecast for the global ocean decades in the future. Along the West Coast, it’s as if the future is here now,” Klinger said. The researchers were a part of The West Coast Ocean Acidification and Hypoxia Science Panel, which will continue to analyze the present conditions along the West Coast and offer suggestions for improvement and curbing the impact of stressors. “If these efforts don’t happen – and I’m not holding my breath – what we’ve seen so far off the West Coast is nothing relative to what lies in store for much of the ocean,” Somero said.